Method of manufacturing iron oxide



l-l. c. STEWART METHOD 0F MANUFAGTURNG RON OXIDE Filed May 5, 1925 4"l ATToRNEY.

4Patented Sept. 20,

UNITED STATES 'nanny CARLISLE A i,aizius vPAT-imi oFFicE.

STEWART, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO THE WESTMORELAND CHEMICAL @c COLOR COMPANY, OF -PHILADELPIA, PENNSYL-- VANIA, A CORPORATION OF PENNSYLVANIA.

.METHOD or MANUFACTURING IaoN oxrnn.

Application ille'd May 3,

My invention rela-tes to the method hof manufacturing oxide of iron for' use in .the manufacture of pigments of various kinds..

O ne method employed in the manufacture of oxide of iron consists in the roasting or burning of ferrous sulphate or copperas (FeSO'yI-IZO) in suitable furnaces, preferably rotary kilns of a-character similar t0 those employed. in the manufacture of ce- .10 ment. In the process of burning the copperas gases of various kinds are given 0E which unless neutralized or eliminated before being discharged into the atmosphere are apt to result in injury to various surrounding objects, such as vegetation, wearing apparel, etc. In addition to the lgases of combustion'which are discharged from the kiln ma be mentioned also-sulphurous oxide (SO2 and sulphuric oxide (S03). The latter, if there happens to be asuiiicient amount of moisture in' thev air, combines therewith to form sulphuric acid which may deposit upon surrounding` objects of the character above indicated and cause injury thereto.

One of the objects, therefore, of my invention is to provide new and novel means which may effect in a practical way the elimination of the deleterious gases, particularly sulphuric oxide, from the gases discharged from the furnace or kiln so as to prevent the discharge of the same into the air from a smoke stack or other conduit for conveying the gases from the furnaceor kiln.

A further object of my invention is to provide an improvement in the manner or method of introducing the copperas into the furnace or kiln wherein it is to be incinerated in such manner as to efect a more satisfacto and efficient incineration thereof.

still further object of the invention is -to eifect removal from vthe gases discharged f from the furnace .any oxide of iron which iiy be carried thereby from the furnace or fther objects and advantages of my invention will be pointed out in the detailed de-` scription thereof which follows or will be apparent fromv such description.

50 Although the method invented by me is not dependent upon any particular kind lor* construction of apparatus for its practice it Iis-obvious that some form of a paratus must kbe employed in connection wit the carrying i923. seriai 110.636,43. A

out of the sam'e. In the accompanying drawing I have shown a view partially in side and partially in sectional elevation of a novel construction of apparatus employed in the carrying out of the'method or process em` bodying my invention.

An apparatus ein# bodying the rinciple of construction as illustrated in t e said drawing has been em-` ployed in actual operation and 'has been found to operate in an and eilicient manner` Referring to the drawing; 1 designates a entirely satisfactory rotary kiln of known construction 'supported in known manner and rotated in known manner by means, as indicated at 2. 3 designates an apparatus employing an underfeed stoker construction for supplying a iame through an opening at 4 by means yof which the'copperas suppliedat the smaller upper end of the kiln is incinerated or burned so as to decompose the same-and obtain at the lower end of the kiln the'product desired; namely, ferrie oxide (FezOa), For the purpose of supplying the c opperas to the upper end portion of the kiln cylinder 1 I have provided a tube 110, the lower end of which terminates Within the said upper end. 'At its upp cylinder adjacent its er end the tube 10 is connected with a branch tube 11 into which a funnel-like hopper 12 opens and through 'which the copperas is supplied to the branch tube 11.

For the purpose of driving the copperas forward through the tube 10 into the kiln cylinder l the branch tube 11 is ex-A tended beyond tlie point of connection of the hopper 12 thereto to an air blower or pump 13 which forces the air through the branch Itube 11 andthrough the tube 10 to cause the saidocopperas to properly feed through the said tubes -11 and 10. In order to prevent the rapidly moving column of air which is discharged from the blower'l?)` fro acting against the column of material owing from the hopper 12 I have provided a baiiieplate or protecting plate 15 which extends partially over the lower open end of the connection of the hopper tube 11.

12 tov the branch In .order to prevent ,the copperas from partially melting and end portion caking in the lowerofthe tube 10 .I have surround.

ed such portion with a larger tube 17 of cony siderably greater diameter than the` tube l0 'so that a cylindrical sp ace annular 'in crossles 15 into the -section is formed between the said tube 10 and the tube 17. The latter tube is provided adjacent its upper end with openings v20 the presence of which allows air to enter into the space between the said tubes and 17.

The forcing of the air from the air pump or blower 13 through the ipe 10 causes the copperas to be discharge from the lower 10 end of the latter pipe forwardly into the er end of the kiln cylinder, as indicated at 21.

The gases of combustion and other gases driven off from the copperas issue from the upper end of the kiln cylinder 1 -into a conduit 30 which extends downwardly from the point of delivery of the gases thereinto and joins a horizontal portion 18 having a downwardly inclined bottom, as indicated at 31, and thence upwardly, as indicated at 32, and through a passageway 33 over the upperoedge of a wall 34 and thence downwardly into the lower end of a smoke stack 35 or other suitableconduit or car rying away the gases. Inorder to eliminate from these gases such of them, particularly the sulphuric oxide, as might become in- 3:5A jurious if allowed to be discharged into the air the said gases as they travel upwardly at 32 are subjected to a washing or scrubbing action'. This scrubbing action is eiected by the introduction of lwater from a pipe 35 40 on to a screen or perforated sheet. 36 of suitable material, such as asbestos situated above the portion 32 of the conduit or passageway. The water streami down through these perforations through. t e gases flowing upwardly through the portion of the conduit at 32 combines with any sulphuric ,oxide (S03) which may be present andremoves the same. This water flows from the chamber 31 through a pi e 37 into a well,

not shown, and is therea ter caused to iiow upwardly through the pi e 35 by means of a steam inspirator, as in cated at 38.

As a result of subjecting the to a washing or scrubbing action by the Water flowing downwardly through the perforar tionsof the sheet 36 they vare rendered heavy so that it is necessary to provide some means to both dry the same' .and create a draft through the conduit of the smoke Stack 85 naine this 1st day upwardly there-y This may be effected by the introducso as to cause them to flow 1n.

tion into the said conduit at a point near.v

the bottom thereof of a column of heated air or other gas. I have lfound that this column of heated air and gases may be supplied from the lire of a stove 40 from which gases it is apparent that even though the air may contain large quantities of water vapor no sulphuric acid will be formed and in consequence 'there can be no injury to ,ob'ects in the vicinity of the apparatus or plant as heretofore has been the case.

As the gases flow through the conduit 30, 31, 32, etc. to the lower end offthe smoke stack-35 the greater proportion of an ferrie oxide which may have been'carrie alon therewith is deposited andmay be recovered? The process as above described may be employed also in the treatment of other sulphur compounds, such as iron sulphid, copper sulphid, and copper sulphate. A.

It will be seen that by my invention I have provided a method and apparatus by the employment of which more eiiicient and economical incineration of the copperas and other sulphur com ounds may and whereby also t ferrie oxide which may have been conveyed from the furnace or kiln may be recovered.

Having thus described my invention what I laim and desire to secure by Letters Paten 1s:

1. The method of manufacturing iron e effected oxide which comprises the delivery of dry;-

copperas with a blast of air into a furnace and thereafter incinerating the said copperas within the said furnace.

2. The, method of manufacturing iron oxide which comprises the delivery of dry copperas mixed with a blast of air upper end of a 'rotating furnace and there# a e greater proportion ofv into the ter incinerating the'saidcopperas within the said furnace.

In testimony that I claim-the foregoingas my invention, I have hereunto signedgm j of Maiy, A .D., 1923.v ,'j HENRY CARLIS E STEWART.' 

